MSP430 I2C HTS221 Humidity Temperature sensor

void ConfigUSCIB0_I2C(void)

{	 
	   //Before doing anything else, put the UCS_B0 port into reset
	   UCB0CTL1 |= UCSWRST;	   

	    UCB0CTL0 = (UCMST | UCMODE_3  | UCSYNC);
	   //Select ACLK as input clk but still keep the port in reset
	   UCB0CTL1 |= UCSSEL__ACLK;

	   UCB0BR0  = 38;      //3.801088MHz / 38 = 100KHz
	   UCB0BR1  = 0;         //upper divisor

	   //take the port out of reset
	   UCB0CTL1 &= ~UCSWRST;

}

void HUM_TEMP_IO_Read(void)
{	

	// TURN SENSOR ON 
	UCB0I2CSA = 0x5F;                     // Slave Address is 0x5Fh (If include Read/Write bit BEh (write) and BFh (read)
	UCB0CTL1 |= UCTR + UCTXSTT;             // I2C TX, start condition
	UCB0TXBUF = 0x20;  		                 // CTRL_REG1 address
	while (UCB0CTL1 & UCTXSTT);             // Wait for start condition and data to send
	while (UCB0IFG & UCTXIFG);
	while (!(UCB0IFG & UCTXIFG));
	UCB0TXBUF = 0x84;			 // Turn on Sensor PD = 1 BDU = 1
	while (UCB0IFG & UCTXIFG);
	while (!(UCB0IFG & UCTXIFG));
	UCB0CTL1 |= UCTXSTP;                    // I2C stop condition
	while (UCB0CTL1 & UCTXSTP);             // Ensure stop condition got sent

	__no_operation();
	__no_operation();

	// SET FOR ONE SHOT
	UCB0I2CSA = 0x5F;                     // Slave Address is 0x5Fh (If include Read/Write bit BEh (write) and BFh (read)
	UCB0CTL1 |= UCTR + UCTXSTT;             // I2C TX, start condition
	UCB0TXBUF = 0x21;  		                 // CTRL_REG2 address
	while (UCB0CTL1 & UCTXSTT);             // Wait for start condition and data to send
	while (UCB0IFG & UCTXIFG);
	while (!(UCB0IFG & UCTXIFG));
	UCB0TXBUF = 0x01;			// One shot mode
	while (UCB0IFG & UCTXIFG);
	while (!(UCB0IFG & UCTXIFG));
	UCB0CTL1 |= UCTXSTP;                    // I2C stop condition
	while (UCB0CTL1 & UCTXSTP);             // Ensure stop condition got sent

	__no_operation();
	__no_operation();

	while(1)
	{
	UCB0CTL1 |= UCTR + UCTXSTT;             // I2C TX, start condition
	UCB0TXBUF = 0x27;  		                 // Status Reg addres
	while (UCB0CTL1 & UCTXSTT);             // Wait for start condition and data to send

	UCB0CTL1 &= ~UCTR;		//Read mode
	UCB0CTL1 |= UCTXSTT;                    // I2C start condition
	while (UCB0CTL1 & UCTXSTT);             // Wait for start condition and data to send
	//UCB0IFG &= ~UCRXIFG;                  // Clear USCI_B0 RX int flag
	UCB0CTL1 |= UCTXSTP;                    // I2C stop condition
	while (!(UCB0IFG & UCRXIFG));

	Hum_Temp_Status_Reg = UCB0RXBUF;

	while (UCB0CTL1 & UCTXSTP);             // Ensure stop condition got sent
	__no_operation();
	__no_operation();
	if(Hum_Temp_Status_Reg == 0x03)break;
	}


	UCB0CTL1 |= UCTR + UCTXSTT;             // I2C TX, start condition
	UCB0TXBUF = 0xB0;  		                 // Status Reg addres
	while (UCB0CTL1 & UCTXSTT);             // Wait for start condition and data to send

	UCB0CTL1 &= ~UCTR;
	UCB0CTL1 |= UCTXSTT;                    // I2C start condition
	while (UCB0CTL1 & UCTXSTT);             // Wait for start condition and data to send
	//UCB0IFG &= ~UCRXIFG;                  // Clear USCI_B0 RX int flag

	 for (i = 0; i< 16; i++)
	    {

	        if (i == 15)
	        {
	            UCB0CTL1 |= UCTXSTP;                    // I2C stop condition
	        }

	        while (!(UCB0IFG & UCRXIFG));		//wait for read buffer full
	        Read_Buffer_Array[i] = UCB0RXBUF;     // Load RXBuffer, start getting next one.

	    }


	while (UCB0CTL1 & UCTXSTP);             // Ensure stop condition got sent
	__no_operation();
	__no_operation();



	H0_rH_x2 = Read_Buffer_Array[0];
	H1_rH_x2 =Read_Buffer_Array[1];
	T0_degC_x8 = Read_Buffer_Array[2];
	T1_degC_x8 = Read_Buffer_Array[3];
	T0_msb = Read_Buffer_Array[5] & 0x03;
	T1_msb = (Read_Buffer_Array[5] & 0x0C) >> 2;
	H0_T0_OUT = (INT16) ((INT16) Read_Buffer_Array[7] << 8 | Read_Buffer_Array[6]);
	H1_T0_OUT = (INT16) ((INT16) Read_Buffer_Array[11] << 8 | Read_Buffer_Array[10]);
	T0_OUT = (INT16) ((INT16) Read_Buffer_Array[13] << 8 | Read_Buffer_Array[12]);
	T1_OUT = (INT16) ((INT16) Read_Buffer_Array[15] << 8 | Read_Buffer_Array[14]);

	 outT0 = ((INT16) T0_msb << 8) | T0_degC_x8;
	 outT1 = ((INT16) T1_msb << 8) | T1_degC_x8;

		UCB0CTL1 |= UCTR + UCTXSTT;             // I2C TX, start condition
		UCB0TXBUF = 0xA8;  		                 // Status Reg addres
		while (UCB0CTL1 & UCTXSTT);             // Wait for start condition and data to send

		UCB0CTL1 &= ~UCTR;
		UCB0CTL1 |= UCTXSTT;                    // I2C start condition
		while (UCB0CTL1 & UCTXSTT);             // Wait for start condition and data to send

		//UCB0IFG &= ~UCRXIFG;                  // Clear USCI_B0 RX int flag
		 for (i = 0; i< 4; i++)
		    {
		       if (i == 3)
		       {
		       	 UCB0CTL1 |= UCTXSTP;                    // I2C stop condition
		       }

		        while (!(UCB0IFG & UCRXIFG));			//wait for read buffer full
		        Read_Buffer_Array[i] = UCB0RXBUF;     // Load RXBuffer, start getting next one.

		    }


		while (UCB0CTL1 & UCTXSTP);             // Ensure stop condition got sent
		__no_operation();
		__no_operation();

		humidityCount = (INT16) ((INT16)Read_Buffer_Array[1] << 8 | Read_Buffer_Array[0]);
		temperatureCount = (INT16) ((INT16)Read_Buffer_Array[3] << 8 | Read_Buffer_Array[2]);

HTS221_humidity = (((float)humidityCount - (float)H0_T0_OUT)/((float)H1_T0_OUT - (float)H0_T0_OUT))*((float)H1_rH_x2 - (float)H0_rH_x2)/2 + (float) H0_rH_x2/2;
HTS221_temperature = (((float)temperatureCount - (float)T0_OUT)/((float)T1_OUT - (float)T0_OUT))*((float)outT1 -(float)outT0)/8 + (float) outT0/8;

	__no_operation();
	__no_operation();

}